Automotive cruise control



June 15, 1965 J. D. BOHL ,1

AUTOMOTIVE CRUISE CONTROL Filed June 24, 1963 INVENTOR. JQHIV D. 50.

fiTTOE/VEY rod 12 to the throttle closed position.

United States Patent O 3,189,120 AUTOMOTIVE CRUISE CONTROL John D. Bohl, South Bend, Ind., assignor to The Bendix Corporation, South Bend, Ind., a corporation of Delaware Filed June 24, 1963, Ser. No. 290,048 5 Claims. (Cl. 1808'2.1)

This invention relates to a cruise control system for automatically controlling the speed of an automotive vehicle and more particularly to improvements in a cruise control system of the type disclosed in copending application Serial No. 184,073, now abandoned.

An object of this invention is to provide a cruise control system which includes means for insuring that the cruise control system will be rendered inoperable simply by momentarily applying the brakes.

More specifically, this invention relates to the use of an electrical circuit in combination with a pneumatic system wherein the electrical circuit includes a plurality of switches in series, one of which is a brake switch and another of which is a vacuum switch which is normally closed but which will open when manifold vacuum increases to a predetermined value. Thus, momentary application of the brakes will open the brake switch and render the pneumatic system of the cruise control inoperable. With the pneumatic system rendered inoperable the throttle will be closed and manifold vacuum will rise.

This increase in vacuum to a predetermined value will cause the vacuum switch to open and will insure that the cruise control system has become nonfunctional.

The above and other objects, features, and advantages of the invention will become apparent from the following description taken in connection with the accompanying drawing which forms a part of this invention.

Referring to the drawing in which the pneumatic and electrical components of the speed control system are schematically and diagrammatically illustrated, it will be seen that the system includes a vacuum power unit having a throttle actuator diaphragm 11 therein which is linked to the engine throttle 13 by rod 12 through a suitable lost motion connection 14. It will be noted that movement of rod 12 to the left will cause the throttle 13 to open and increase the fuel supply to the engine, such movement being against spring 15 which urges the throttle towards a closed position. A spring 16 urges the actuator diaphragm 11 to a throttle released position. The actuator diaphragm 11 has one side thereof continually open to atmosphere while the other side thereof is connected by a conduit 18 to a three-way solenoid valve, indicated generally by the numeral 20. The

solenoid valve includes an armature 22 connected to a valve stem 24 on which is mounted a valve head 26. This valve has a vacuum port 27 connected to conduit '28 and an air port 30. Conduit 28 leads to a variable 30, thereby communicating the power unit 10 with vacuum from the intake manifold. When the solenoid is deenergized, no pressure differential exists across actuator diaphragm 11, and the spring 16, therefore, urges At such times manual operation of the throttle 13 is not impeded due to the lost motion connection on the link.

altar-2s Patented June 15, 1965 It will be noted that the servo control system comprising fixed orifice 38, conduit 36, conduit 28 and governor variable orifice 32 will remain functional at all times during vehicle operation and the pressure in con duit 28 will be regulated in accordance with the existing governor setting, said governor setting being adjustable in the manner disclosed in copending application Serial No. 184,073. Thus, whenever the vehicle speed is below the governor setting, the variable orifice 32 will be closed by modulating valve 35 and manifold pressure will exist in conduit 28. If the speed of the vehicle increases and passes the governor preset speed setting, the modulating valve 35 will move away from the variable orifice 32 and the pressure in conduit 28 will increase (vacuum will decrease) since this conduit will be put in communication with the atmosphere. At some speed slightly above the governor setting, the governor valve will be wide open and the pressure in conduit 28 will approach atmospheric pressure and will be substantially higher than manifold pressure. However, these variations in pressure will not affect the throttle as long as solenoid valve 20 is not energized. When the solenoid valve 20 is energized, it will open vacuum port 27 to the power unit 10 and will close the air port 30. In

this condition, the system will regulate the vehicle speed in a manner to be subsequently described.

The control for the previously described pneumatic system includes a conduit 42, one end of which communicates with a chamber 44 of a differential pressure switch (vacuum switch) 46 and the other end of which communicates with conduit 36 at a point between fixed orifice 38 and the intake manifold 40. The other chamber 48 of the vacuum switch is open to atmosphere through port 50. A diaphragm 52 separates the chambers 44 and 48 and is urged by a spring 54 towards electrical switch contacts 56 and 58 which are positioned in the wall of chamber 48 and are adapted to be interconnected by contact with the diaphragm support plate 60 when the force of the spring 54 is suificient to overcome any pressure difference existing across the diaphragm.

Referring now to the electrical circuit of the drawing, it will be noted that it includes a battery 62 having one terminal grounded at 64 and having the other terminal connected to an ignition switch 66. Other circuits lead from the ignition switch and are indicated generally by line 68. A cruise control circuit line 70 also leads from the ignition switch 66 to an onf-otf switch 72 located in the drivers compartment and conveniently made a part of the speed setting control so that it will be in an on position when the speed selector is moved to any given selected speed position. Circuit 70 continues in series through a shift interlock switch 74 which is open in the park, neutral, and reverse positions but is closed in the drive positions, and a brake switch 76 which is normally closed but is opened upon application of the brakes. Although the shift interlock switch is defined in terms of automatic transmission gear shift settings, it will be understood by those skilled in the art that certain adaptationsin the control circuit would permit the use of the invention in an automobile which does not have an automatic transmission.

From the brake switch, circuit 70 branches and passes in parallel through coil 78 of a normally open holding relay switch 80 and the coil 82 of the solenoid valve 20. A branch circuit 86 leads from circuit 70 to contact 88 of the relay switch and from pole 90 of the relay switch to ground at 92. Circuit 70 continues in series beyond coils 78 and 82 to contact 56 of the vacuum pressure switch 46 and thence from contact 58 to switch 98 which is suitably connected to governor 34. Switch 98 is connected to ground at 94.

p, rib

It will be noted that the structure of governor 34 includes a lost motion element 96 between the governor weight structure and the governor valve 32. This lost motion connection is utilized to mechanically close switch 98, which is connected into circuit 70, when a predetermined vehicle speed is reached. It will be obvious that this lost motion connection will permit overtravel in the governor so that control switch 98 will close before governor valve 35 will open.

Operation of the speed control system will be as follows: After a governor speed setting is made and the of-off switch 72 is closed, the vehicle is set in motion in forward drive so that the ignition and interlock switches 66 and '74 are also closed. When the vehicle has been accelerated under manual control to a given predetermined vehicle speed, the switch 98 will close, as a result of movement by the governor weights, thereby completing circuit 70. It should be understood, however, that circuit 70 will be completed only if the vacuum switch is closed and that this will normally be the case except when manifold vacuum reaches approximately 18 in. Hg. The throttle position for such a vacuum reading will be a relatively closed one. Complete closure of the throttle will cause the manifold vacuum to rise to approximately 24 in. Hg.

With the circuit 70 completed solenoid valve 20 will become energized and thus permit communication of vacuum from the intake manifold to the power unit via vacuum port 27. This will create a pressure differential across actuator diaphragm 11 of suflicient magnitude to permit regulation of the throttle and maintenance of a substantially uniform vehicle speed until the circuit is broken. The holding relay switch 80 is energized simultaneously and closes contacts 88 and 90 to provide a permanent ground for circuit 70 regardless of subsequent opening and closing of switch 98. Thereafter, if at any time the driver operates his brakes or turns ofif the ignition or moves the shift control out of forward drive, the relay switch 80 will open and the solenoid valve will shift, so as to admit air to the actuator unit It) and permit closure of the throttle 13.

If the invention disclosed herein is not utilized in this type of cruise control system, it should be noted that when the vehicle is moving at or above the set controlling speed a monentary application of the brake pedal may not permanently disengage the cruise control system. Unless the brake application slows the vehicle approximately 2-3 mph. below the set controlling speed, switch g8 may still be closed in which event circuit '70 would be completed once again when the brake switch closes after the monentary application of the brakes. Thus, with the circuit completed solenoid coil 82 will be reenergized, and the cruise control system will still be functioning. However, by inserting vacuum switch 46 in series into the circuit, and by utilizing a spring 54 which will maintain the vacuum switch in a closed position until manifold vacuum reaches a predetermined value (eg. 18 in. Hg.), it is possible to insure that a momentary application of the brakes will be sufficient to cause deenergization of solenoid coil 82 and consequently render the cruise control system nonfunctional until the driver performs the necessary steps to render it functional once again. Thus, with the vehicle traveling under cruise control at the set speed, or above the set speed by manually accelerating to such higher speed, a momentary application of the brake pedal will break circuit 70 and will cause solenoid coil 82 to momentarily become deenergized. Such deenergization will permit throttle 13 to close and as a result manifold vacuum will rise to approximately 24 in. Hg. This rise in vacuum will cause the vacuum switch to also open so that even if the vehicle has not slowed below the set speed and switch 98 is still closed, release of the brake pedal and subsequent closure of the brake switch will not result in reenergization of solenoid coil 82 since the vacuum switch will be open.

It should be understood that the driver may subsequently energize solenoid coil 82 and render the cruise control system operable simple by accelerating the vehicle to the set speed at which time switch 98 will close and vacuum switch 46 will have closed because of the drop in manifold vacuum.

Although this invention has been described in connection with a power unit which utilizes vacuum as a power source, any fluid pressure source may be used which varies as a function of the movement of the throttle control member. Accordingly, when the term fluid pressure is referred to in the claims, it is intended that such expression be broad enough to cover any suitable fluid pressure which is available in vehicles of this character and to include vacuum.

Furthermore, even though this invention has been described in connection with a specific embodiment, it will be obvious to those skilled in the art that various changes may be made in the form, structure, and arrangement of parts without departing from the spirit of the invention. Accordingly, I do not desire to be limited to the specific embodiment disclosed herein primarily for purposes of illustration, but instead desire protection falling within the scope of the appended claims.

Having thus described the various features of the invention, What I claim as new and desire to secure by Letters Patent is:

1. In an automotive vehicle having an engine and a driver operated throttle control member for controlling the fuel supply to the engine, fluid pressure means for regulating and controlling movement of said throttle control member to a position for maintaining said vehicle at a predetermined speed, said fluid pressure varying as a function of the movement of the throttle control member, valve means having first and second positions for controlling the application of fluid pressure to said fluid pressure means, solenoid means operatively connected to said valve means for causing movement thereof from said first to said second position upon energization of said solenoid means, and an electrical circuit for energizing said solenoid means, said circuit including a plurality of switches in series, one of which is a normally closed fluid pressure safety switch which is operatively connected to said fluid pressure means and controlled by a predetermined variation of fluid pressure therefrom, said safety switch being opened to insure deenergization .of said solenoid means when said fluid pressure reaches a predetermined value as a result of temporary opening of one of said other switches.

2. The combination defined in claim 1 wherein said fluid pressure means comprises vacuum from the intake manifold of the engine and said switch which may be tem porarily opened is a brake switch which is normally closed but is opened upon application of the brakes.

3. In an automotive vehicle having an internal combustion engine and a driver operated throttle control member for controlling the fuel supply to the engine, a pressure responsive element operatively connected to said throttle control member for regulating and controlling movement thereof, passage means for communicating vacuum from the intake manifold of said engine to said pressure responsive element, valve means located in said passage means and having first and second positions for controlling the application of vacuum to said pressure responsive element, solenoid means operatively connected to said valve means for causing movement thereof from said first to said second position upon energization of said solenoid means, and an electrical circuit for energizing said solenoid means, said circuit including a plurality of switches in series, one of which is a normally closed vacuum safety switch which is operatively connected to the intake manifold of said engine, said safety switch being opened to insure deenergization of said solenoid means when manifold vacuum increases to a predetermined value as a result of temporary opening of one of said other switches.

4. In an automotive vehicle having an internal combustion engine and a driver operated throttle control member for controlling the fuel supply to the engine, a pressure responsive element operatively connected to said throttle control member for regulating and controlling movement thereof, passage means for communicating vacuum from the intake manifold of said engine to said pressure responsive element, valve means located in said passage means and having first and second positions for controlling the application of vacuum to said pressure responsive element, solenoid means operatively connected to said valve means for causing movement thereof from said first to said second position upon energization of said solenoid means, and an electrical circuit for energizing said solenoid means, said circuit including a plurality of switches in series, one of which is a speed selector switch which can be manually moved to a closed position, another of which is a brake switch which is normally closed but is opened upon application of the brakes, a third of which is a speed responsive switch which is open at vehicle speeds below a predetermined valve but is automatically closed at vehicle speeds above a predetermined value, and a fourth of which is a normally closed vacuum safety switch which is operatively connected to the intake manifold of said engine, said safety switch being opened to insure deenergization of said solenoid means when manifold vacuum increases to a predetermined value as a result of opening of said brake switch.

5. In an automotive vehicle having an internal combustion engine and a driver operated throttle control member for controlling the fuel supply to the engine, a vacuum power unit having a pressure responsive element located therein, said pressure responsive element being operatively connected to said throttle control member for regulating and controlling movement thereof, first passage means for communicating vacuum from the intake manifold of said engine to one side of said pressure responsive element, said vacuum varying as a function of the movement of the throttle control member, first valve means located in said first passage means, said valve means having a first position for communicating atmosphere pressure to the vacuum side of said pressure responsive element and a second position for preventing communication therebetween, solenoid means operatively connected to said first valve means for causing movement thereof from one position to the other independently of vehicle speed, second passage means for communicating atmospheric pressure to the vacuum side of said pressure responsive element when said first valve is in said second position, modulating valve means interposed in said second passage means for regulating the degree of communication between the atmosphere and the vacuum side of said pressure responsive element via said second passage means, means responsive to vehicle speed operatively connected to said modulating valve for controlling movement thereof, a second vacuum unit having a pressure responsive member located therein, passage means for communicating one side of said pressure responsive member with vacuum from the intake manifold of said engine and the other side thereof with atmosphere, and an electrical circuit for energizing and deenergizing said solenoid means, said circuit including an ignition switch which is closed upon turning of the ignition key, a shift interlock switch which is open in the park, neutral and reverse positions but is closed in the drive positions, a speed selector switch which is open when the selector is in an off position but is closed when the selector is moved to any given selected speed position, a brake switch which is normally closed but is opened upon application of the brakes, a speed responsive switch which is open at vehicle speeds below a predetermined value but is automatically closed at vehicle speeds above a predetermined value, a holding switch for holding said solenoid means energized after said speed responsive switch has opened, and a normally closed safety switch operatively connected to the pressure responsive member of said second vacuum unit, said safety switch being opened when manifold vacuum increases to a predetermined value and causes movement of said pressure responsive member away from its normally closed position.

References Cited by the Examiner UNITED STATES PATENTS 2,990,825 7/61 Fuller et al. -82.1 X

A. HARRY LEVY, Primary Examiner. 

1. IN AN AUTOMOTIVE VEHICLE HAVING AN ENGINE AND A DRIVER OPERATED THROTTLE CONTROL MEMBER FOR CONTROLLING THE FUEL SUPPLY TO THE ENGINE, FLUID PRESSURE MEANS FOR REGULATING AND CONTROLLING MOVEMENT OF SAID THROTTLE CONTROL MEMBER TO A POSITION FOR MAINTAINING SAID VEHICLE AT A PREDETERMINED SPEED, SAID FLUID PRESSURE VARYING AS A FUNCTION OF THE MOVEMENT OF THE THROTTLE CONTROL MEMBER, VALVE MEANS HAVING FIRST AND SECOND POSITIONS FOR CONTROLLING THE APPLICATION OF FLUID PRESSURE TO SAID FLUID PRESSURE MEANS, SOLENOID MEANS OPERATIVELY CONNECTED TO SAID VALVE MEANS FOR CAUSING MOVEMENT THEREOF FROM SAID FIRST TO SAID SECOND POSITION UPON ENERGIZATION OF SAID SOLENOID MEANS, AND AN ELECTRICAL CIRCUIT FOR ENERGIZING SAID SOLENOID MEANS, SAID CIRCUIT INCLUDING A PLURALITY OF SWITCHES IN SERIES, ONE OF WHICH IS A NORMALLY CLOSED FLUID PRESSURE SAFETY SWITCH WHICH IS OPERATIVELY CONNECTED TO SAID FLUID PRESSURE MEANS AND CONTROLLED BY A PREDETERMINED VARIATION OF FLUID PRESSURE THEREFROM, SAID SAFETY SWITCH BEING OPENED TO INSURE DEENERGIZATION OF SAID SOLENOID MEANS WHEN SAID FLUID PRESSURE REACHES A PREDETERMINED VALUE AS A RESULT OF TEMPORARY OPENING OF ONE OF SAID OTHER SWITCHES. 